This invention relates to a method of repairing cracked or fractured thin metal parts, and more particularly to a method of repairing cracked or fractured thin metal parts such as one eighth inch cast iron and one quarter inch cast aluminum.
Past practice of repairing thicker metal parts is to use fasteners commonly known as "chain-locks", "metalocks", and "seal-locks" without the application of heat. Such a method is described in my prior U.S. Pat. No. 2,998,645.
This method enabled the repair of cracks in metal walls of automobile cylinder blocks, large pipes, valves, transmission housings, etc. without the use of external heat. In making automobiles and trucks lighter, manufacturers have been decreasing the weight by making engine blocks of much thinner cast iron or from cast aluminum. These thinner cast iron and aluminum parts have led to problems when the old method of crack repair has been attempted.
Since most repair plugs are made of cast iron or steel, the repair plugs are stronger than the thinner cast iron or cast aluminum being repaired. Therefore, turning of the repair plugs into the tapped and threaded holes in the thinner cast iron or cast aluminum causes the plugs to continue tapping the hole so that the plug is never really snug to make a proper seal against water pressure, air pressure, or compression.
While my solution to the above-identified problem seems simple once disclosed, no other individual skilled in the art of crack repair has discovered the solution prior to me.